1. Field of the Invention
The present invention relates to an ink jet recorder having a recording head for ejecting ink. In particular, the invention relates to an ink jet recorder capable of recording at substantially constant density regardless of temperature variation.
2. Description of Related Art
A known ink jet recorder like an ink jet printer includes a recording head, which has ink chambers or passages each defined between piezoelectric ceramic partition walls. One end of each passage is connected to an ink cartridge or another ink supply means. The head also has nozzles each communicating with the other end of one of the passages. In accordance with print data, the walls can be deformed to change the volume of the passages. When the volume of each passage decreases, ink is ejected in the form of a droplet from the passage through the associated nozzle onto a recording medium. When the volume of each passage increases, ink is supplied from the associated cartridge to the passage.
The viscosity of ink varies with ambient temperature. Therefore, if the drive voltage for the piezoelectric walls is constant, the volume of ejected ink and the ink ejection speed increase as the ambient temperature rises. In this case, as the temperature rises, the recording density increases. This makes it difficult to print at constant density. The variation in recording density may make the recorder user feel bad.